Electronic documents such as web pages, emails and instant messages often contain links that can be used to navigate to other documents, such as web pages.
Such links frequently go to a location unintended by the user, such as a phishing site. In many cases, such as in the case of “phishing” messages or web sites hosting malicious content (either intentionally or inadvertently), such a location may be associated with malicious document, which can cause harm such as installation of malicious software or theft of personal information.
Previous technologies for preventing phishing include interception of a phishing message, prevention of site spoofing, or detection of navigation to a malicious site. However, no current filter is effective against all phishing messages, sites can be spoofed despite the current countermeasures, detection of malicious site navigation is error-prone, and users may use devices or networks that are exempt from firewalls and other real-time checks that may be instituted. Furthermore, detection of a malicious site at the time an email is received can sometimes result in a false negative because an attacker can change site contents or DNS results so a security check may initially succeed, but the destination may change by the time a user clicks through to a malicious site
It would therefore be useful to be verify that a user's attempted navigation to a link destination will result in navigation to a site that is verified not to be suspicious.